Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known foil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
In many cases, accessory components are attached to the rotor blades of wind turbines to perform various functions during operation of the wind turbine. For example, it is known to change the aerodynamic characteristics of wind turbine rotor blades by adding protrusions or other structures to the surface of the blade. Such structures increase the energy conversion efficiency during normal operation of the wind turbine by increasing the lift force of the blades while decreasing the drag force. Example components include winglets, tip extensions, vortex generators, and the like. The purposes and operational principals of these devices are well understood by those skilled in the art.
For example, U.S. patent application Ser. No. 14/706,024 entitled “Attachment Method and System to Install Components, Such as Tip Extensions and Winglets, to a Wind Turbine Blade” filed on May 7, 2015, which is incorporated herein by reference in its entirety, describes a tip extension for a wind turbine rotor blade. The tip extension of the aforementioned patent application has a sock-type configuration that slides onto the blade tip of the rotor blade so as to modify the aerodynamic properties of the blade tip. Once installed, the tip extension can create a chord-wise step at the trailing edge of the inboard tip extension between the tip extension and the rotor blade shell. Such a step can create airflow and/or noise concerns. Thus, the industry would benefit from a tip extension assembly that minimizes negative impacts to the aerodynamic profile of the rotor blade, thereby reducing associated noise.
Accordingly, the present disclosure is directed to a tip extension assembly that includes one or more chord extensions configured adjacent to a sock-type tip extension so as to provide a transition between the aforementioned chord-wise step and the surface of the rotor blade.